From 5f93cc8a653e47dd8c426101567f2b91c4e3482d Mon Sep 17 00:00:00 2001
From: Eddy Pedroni <epedroni@pm.me>
Date: Thu, 24 Jul 2025 18:59:30 +0200
Subject: Fix race condition, check port before sending message

---
 daemon/src/device_connection.h | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/daemon/src/device_connection.h b/daemon/src/device_connection.h
index 58ddd7f..5f2b051 100644
--- a/daemon/src/device_connection.h
+++ b/daemon/src/device_connection.h
@@ -7,6 +7,7 @@
 #include <rtmidi/RtMidi.h>
 
 #include <string>
+#include <mutex>
 
 namespace midi_router
 {
@@ -27,11 +28,13 @@ struct Device_Connection : public Sender
     Submitter & submitter;
     RtMidiIn midi_in {};
     RtMidiOut midi_out {};
+    std::mutex mutex {};
 
     void
     send(std::vector<std::uint8_t> const & payload) override
     {
-        midi_out.sendMessage(&payload);
+        const std::lock_guard<std::mutex> lock(mutex);
+        if (midi_out.isPortOpen()) midi_out.sendMessage(&payload);
     }
 
     std::string
@@ -43,6 +46,7 @@ struct Device_Connection : public Sender
     void
     connect(std::size_t port)
     {
+        const std::lock_guard<std::mutex> lock(mutex);
         if (!midi_in.isPortOpen()) midi_in.openPort(port);
         if (!midi_out.isPortOpen()) midi_out.openPort(port);
     }
@@ -50,6 +54,7 @@ struct Device_Connection : public Sender
     void
     disconnect()
     {
+        const std::lock_guard<std::mutex> lock(mutex);
         if (midi_in.isPortOpen()) midi_in.closePort();
         if (midi_out.isPortOpen()) midi_out.closePort();
     }
-- 
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